Posts Tagged ‘Windows 2008R2 SP1’

Hyper-V R2 and right numbers of physical NIC’s

April 27, 2011 1 comment

When it comes to network configuration, be sure to provide the right number of physical network adapters on Hyper-V servers. Failure to configure enough network connections can make it appear as though you have a storage problem, particularly when using iSCSI.

Recommendation for network configuration ( number of dedicated Physical Nic’s ):

  • 1 for Management. Microsoft recommends a dedicated network adapter for Hyper-V server management.
  • At least 1  for Virtual machines. Virtual network configurations of the external type require a minimum of one network adapter.
  • 2 for SCSI. Microsoft recommends that IP storage communication have a dedicated network, so one adapter is required and two or more are necessary to support multipathing.
  • At least 1 for Failover cluster. Windows® failover cluster requires a private network.
  • 1 for Live migration. This new Hyper-V R2 feature supports the migration of running virtual machines between Hyper-V servers. Microsoft recommends configuring a dedicated physical network adapter for live migration traffic. This network should be separate from the network for private communication between the cluster nodes, from the network for the virtual machine, and from the network for storage
  • 1 for Cluster shared volumes. Microsoft recommends a dedicated network to support the communications traffic created by this new Hyper-V R2 feature. In the network adapter properties, Client for Microsoft Networks and File and Printer Sharing for Microsoft Networks must be enabled to support SMB

Some interesting notes when comparing FC with iSCSI:

  • iSCSI and FC delivered comparable throughput performance irrespective of the load on the system.
  • iSCSI used approximately 3-5 percentage points more Hyper-V R2 CPU resources than FC to achieve comparable performance.

For information about the network traffic that can occur on a network used for Cluster Shared Volumes, see “Understanding redirected I/O mode in CSV communciation” in Requirements for Using Cluster Shared Volumes in a Failover Cluster in Windows Server 2008 R2 (

For more information on the network used for CSV communication, see Managing the network used for Cluster Shared Volumes.

It’s not recommend that you do use the same network adapter for virtual machine access and management.
If you are limited by the number of network adapters, you should configure a virtual local area network (VLAN) to isolate traffic. VLAN recommendations include 802.1q and 802.p.

Hyper-V : Virtual Hard Disks. Benefits of Fixed disks

March 31, 2011 5 comments


When creating a Virtual Machine, you can select to use either virtual hard disks or physical disks that are directly attached to a virtual machine.

My personal advise and what I have seen from Microsoft folks is to always use FIXED DISK for production environment, even with the release of Windows Server 2008 R2, which one of the enhancements was the improved performance of dynamic VHD files.

The explanation and benetifts for that is simple:

 1. Almost the same performance as passthroug disks

2. Portability : you can move/copy the VHD

3. Backup : you can backup at the VHD level and better, using DPM you can restore at ITEM level ( how cools is that! )

 4.You can have Snapshots

 5. The fixed sized VHD performance has been on-par with the physical disk since Windows Server 2008/Hyper-V

 If you use pass-through disks you lose all of the benefits of VHD files such as portability, snap-shotting and thin provisioning. Considering these trade-offs, using pass-through disks should really only be considered if you require a disk that is greater than 2 TB in size or if your application is I/O bound and you really could benefit from another .1 ms shaved off your average response time.  

 Disks Summary table:

Storage Container Pros Cons
Pass-through DisK
  • Fastest performance
  • Simplest storage path because file system on host is not involved.
  • Better alignment under SAN.
  • Lower CPU utilization
  • Support very large disks
  • VM snapshot cannot be taken
  • Disk is being used exclusively and directly by a single virtual machine.
  • Pass-through disks cannot be backed up by the Hyper-V VSS writer and any backup program that uses the Hyper-V VSS writer.
  • Fixed sized VHD
    • Highest performance of all VHD types.
    • Simplest VHD file format to give the best I/O alignment.
    • More robust than dynamic or differencing VHD due to the lack of block allocation tables (i.e. redirection layer).
    • File-based storage container has more management advantages than pass-through disk.
    • Expanding is available to increase the capacity of VHD.
    • No risk of underlying volume running out of space during VM operations
    • Up front space allocation may increase the storage cost when large of number fixed VHD are deployed.
    • Large fixed VHD Creation is time-consuming.
    • Shrinking the virtual capacity (i.e. reducing the virtual size) is not possible.
    Dynamically expanding or                  




    Differencing VHD


    • Good performance
    • Quicker to create than fixed sized VHD
    • Grow dynamically to save disk space and provide efficient storage usage.
    • Smaller VHD file size makes it more nimble in terms of transporting across the network.
    • Blocks of full zeros will not get allocated and thus save the space under certain circumstances.
    • Compact operation is available to reduce the actual physical file size
    • Interleaving of meta-data and data blocks may cause I/O alignment issues.
    • Write performance may suffer during VHD expanding.
    • Dynamically expanding and differencing VHDs cannot exceed 2040GB
    • May get VM paused or VHD yanked out if disk space is running out due to the dynamic growth.
    • Shrinking the virtual capacity is not supported.
    • Expanding is not available for differencing VHDs due to the inherent size limitation of parent disk.
    • Defrag is not recommended due to inherent re-directional layer.

    SCVMM 2008 R2 SP1 : available for download. Support for DM and Remote FX

    March 25, 2011 Leave a comment

    With support for new features of Windows Server 2008 R2 SP1

    • Dynamic Memory: Windows Server 2008 R2 SP1 Hyper-V supports Dynamic Memory enabling customers to better utilize the memory resources of a Hyper-V host. VMM 2008 R2 SP1 allows administrators to create and deploy Virtual Machines onto Windows Server 2008 R2 SP1 Hyper-V hosts and will report on the memory currently in use for these VMs where Dynamic Memory is enabled. Using Dynamic Memory for supported VMs allows for more efficient utilization of memory, with consistent performance, and higher consolidation ratios.
    • Microsoft RemoteFX: Windows Server 2008 R2 SP1 introduces a new set of end user experience enhancements with Microsoft RemoteFX. VMM 2008 R2 SP1 allows administrators to create and deploy Virtual Machines with RemoteFX enabled to qualified Windows Server 2008 R2 SP1 Hyper-V hosts. This enables a rich, local-like desktop environment over the network.

    Hyper-V Integration Services should be updated after applying SP1 on Virtual Machines

    March 10, 2011 3 comments

    Now that you installed SP1 on Hyper-V/Windows 2008 R2 servers, you should upgrade the Integration Services in all virtual machines or have the SP1 installed on the VM’s also.

    To do this using the Virtual Machine Manager, connect to the VM :

    1. Click in ACTION,
    2. C
    lick Insert Integration Services Setup Disk
    3. Click Install Hyper-V Integration Services
    4. Click OK, when a message informing about a previous installation show.

    To check the Integration Services version, look at the Driver version of the Microsoft Virtual Machine Bus Network Adapter in Device Manager

    Uninstalling Windows 2008 R2/Windows 7 SP1 RC to install the RTM version

    March 1, 2011 Leave a comment

    To remove the SP1 RC you have 2 options:

    Option 1, using the GUI

    1 Open the Control Panel->Programs->Programs and Features-> Installed Updates

    2 Select the kb:976932 and click Uninstall

    Option 2 : command

    If you tried to uninstall the SP1 by using the traditional Programs/Features -> updates installed without success, use this one:

    wusa /uninstall /kb:976932

    Windows 2008R2/Windows 7 SP1: Changes common to both client and server platforms

    February 25, 2011 Leave a comment

    Here are the changes common to W2008R2 ad Windows 7, after applying the SP1:

    1. Change to behavior of “Restore previous folders at logon” functionality

    SP1 changes the behavior of the “Restore previous folders at logon” function available in the Folder Options Explorer dialog. Prior to SP1, previous folders would be restored in a cascaded position based on the location of the most recently active folder. That behavior changes in SP1 so that all folders are restored to their previous positions.

    2. Enhanced support for additional identities in RRAS and IPsec

    Support for additional identification types has been added to the Identification field in the IKEv2 authentication protocol. This allows for a variety of additional forms of identification (such as E-mail ID or Certificate Subject) to be used when performing authentication using the IKEv2 protocol.

    3. Support for Advanced Vector Extensions (AVX)

    There has always been a growing need for ever more computing power and as usage models change, processors instruction set architectures evolve to support these growing demands. Advanced Vector Extensions (AVX) is a 256 bit instruction set extension for processors. AVX is designed to allow for improved performance for applications that are floating point intensive. Support for AVX is a part of SP1 to allow applications to fully utilize the new instruction set and register extensions.

    4. Improved Support for Advanced Format (512e) Storage Devices

    SP1 introduces a number of key enhancements to improve support of recently introduced storage devices with a 4KB physical sector size (commonly referred to as “Advanced Format”). These enhancements include functionality fixes, improved performance, and updated storage drivers which provide applications the ability to retrieve information as to the physical sector size of storage device. More information on these enhancements is detailed in Microsoft KB 982018.

    Changes specific to Windows 7 with SP1

    February 24, 2011 Leave a comment

    Here are the specific changes for Windows 7 SP1

    1. Additional support for communication with third-party federation services

    Additional support has been added to allow Windows 7 clients to effectively communicate with third-party identity federation services (those supporting the WS-Federation passive profile protocol). This change enhances platform interoperability, and improves the ability to communicate identity and authentication information between organizations.

    Improved HDMI audio device performance

    A small percentage of users have reported issues in which the connection between computers running Windows 7 and HDMI audio devices can be lost after system reboots. Updates have been incorporated into SP1 to ensure that connections between Windows 7 computers and HDMI audio devices are consistently maintained.

    2. Corrected behavior when printing mixed-orientation XPS documents

    Prior to the release of SP1, some customers have reported difficulty when printing mixed-orientation XPS documents (documents containing pages in both portrait and landscape orientation) using the XPS Viewer, resulting in all pages being printed entirely in either portrait or landscape mode. This issue has been addressed in SP1, allowing users to correctly print mixed-orientation documents using the XPS Viewer.